Abstract: A medical device packaging container includes a tray, a sheet-like lid portion having an annular flange portion, and an annular heat seal portion. The annular heat seal portion includes a first-side seal portion, a second-side seal portion, a third-side seal portion, and a fourth-side seal portion. The first-side seal portion includes a central seal portion, a first side-part seal portion, and a second side-part seal portion. The central seal portion includes central seal extension portions, the first side-part seal portion includes a first side-part seal extension portion, and the second side-part seal portion includes a second side-part seal extension portion.

Abstract: A prefilled syringe includes an outer cylinder, a gasket, a plunger, and a drug housed in the outer cylinder. The outer cylinder includes a flange part that is located at a proximal end part. The plunger includes a gasket pressing part and a shaft part that extends in a proximal end direction from a gasket pressing part. The shaft part includes indicator parts that are located on a proximal side of the gasket pressing part.

Abstract: A packaging box includes a body and a lid. The body includes a bottom surface part, a front surface part rising from the bottom surface part, and protruding pieces positioned at one side portion of the front surface part and extending from an upper edge of the front surface part. The lid includes a top surface part, a lid front surface part, lid side surface parts opposed to each other, and two lid front side joints joined to inner surfaces of both sides of the lid front surface parts. The lid front side joints have cutout portions at the upper end portion, bendable portions below the cutout portion, and a non-joint portion formed between the bendable portions and the lid front surface part, into which the distal ends of the protruding pieces can enter. The lid closed state is maintained by engagement between the protruding pieces and the bendable portions.